HVAC MCA & Electrical Load

HVAC Electrical Load & MCA Calculator is the professional tool for HVAC technicians and electricians. Calculate Minimum Circuit Ampacity (MCA) and Maximum Overcurrent Protection (MOCP) sizing per National Electrical Code (NEC) Article 440 requirements for air conditioning equipment installations.

EQUIPMENT TYPES SUPPORTED:
Split AC Systems — Standard residential split-system air conditioners
Package Units — Rooftop and packaged equipment configurations
Heat Pumps — Electric heat pump systems with auxiliary heating
Mini Split Systems — Ductless mini-split and VRF installations
PTAC Units — Packaged terminal AC for apartments and hotels

VOLTAGE OPTIONS:
Single-Phase: 115V, 208V, 230V (residential and light commercial)
Three-Phase: 208V, 230V, 460V (commercial and industrial)

ELECTRICAL CALCULATIONS (NEC 440):
MCA Sizing — NEC 440.32: 125% of largest motor plus all others
MOCP Selection — NEC 440.22: Maximum overcurrent protection sizing
Wire Size Recommendation — AWG per NEC Table 310.16 ampacity
Breaker Selection — Standard breaker size selection for protection

INPUT PARAMETERS:
Compressor RLA (Rated Load Amps) rating
LRA (Locked Rotor Amps) startup current
Fan FLA (Full Load Amps)
Auxiliary heater load current
Multiple equipment combinations

FEATURES:
100% Offline — No internet connection required for calculations
Works in field without cellular coverage
English & Spanish language support
Dark theme for outdoor visibility

OPTIONAL PRO UPGRADE — $2.99 ONE-TIME IN-APP PURCHASE
The following features require a separate one-time in-app purchase. They are not required to use the calculator:
• Unlimited saved calculation history
• PDF export of results
• Dark theme
• Ad-free experience

WHY ELECTRICIANS & HVAC TECHS USE THIS APP:
Faster electrical load calculations than manual NEC charts
Ensures code-compliant wire and breaker sizing
Prevents undersized circuits that risk failure
Prevents oversized protection that ignores equipment
Cross-check MCA and MOCP calculations
Reduces electrician callbacks and callbacks

PERFECT FOR:
HVAC technicians estimating electrical requirements
Electricians sizing circuits for AC equipment
AC contractors preparing accurate project bids
Electricians qualifying under NEC Article 440
HVAC apprentices learning code requirements
Building maintenance engineers planning upgrades

NEC Article 440 compliant calculations for safe, code-approved AC installations.

Part of HVACTools Suite — professional HVAC technician and AC service tools for field calculations and system diagnostics.